scholarly journals Full-Length Human Chromogranin-A Cardioactivity: Myocardial, Coronary, and Stimulus-Induced Processing Evidence in Normotensive and Hypertensive Male Rat Hearts

Endocrinology ◽  
2013 ◽  
Vol 154 (9) ◽  
pp. 3353-3365 ◽  
Author(s):  
Teresa Pasqua ◽  
Angelo Corti ◽  
Stefano Gentile ◽  
Lorena Pochini ◽  
Mimma Bianco ◽  
...  

Plasma chromogranin-A (CgA) concentrations correlate with severe cardiovascular diseases, whereas CgA-derived vasostatin-I and catestatin elicit cardiosuppression via an antiadrenergic/nitric oxide-cGMP mediated mechanism. Whether these phenomena are related is unknown. We here investigated whether and to what extent full-length CgA directly influences heart performance and may be subjected to stimulus-elicited intracardiac processing. Using normotensive and hypertensive rats, we evaluated the following: 1) direct myocardial and coronary effects of full-length CgA; 2) the signal-transduction pathway involved in its action mechanism; and 3) CgA intracardiac processing after β-adrenergic [isoproterenol (Iso)]- and endothelin-1(ET-1)-dependent stimulation. The study was performed by using a Langendorff perfusion apparatus, Western blotting, affinity chromatography, and ELISA. We found that CgA (1–4 nM) dilated coronaries and induced negative inotropism and lusitropism, which disappeared at higher concentrations (10–16 nM). In spontaneously hypertensive rats (SHRs), negative inotropism and lusitropism were more potent than in young normotensive rats. We found that perfusion itself, Iso-, and endothelin-1 stimulation induced intracardiac CgA processing in low-molecular-weight fragments in young, Wistar Kyoto, and SHR rats. In young normotensive and adult hypertensive rats, CgA increased endothelial nitric oxide synthase phosphorylation and cGMP levels. Analysis of the perfusate from both Wistar rats and SHRs of untreated and treated (Iso) hearts revealed CgA absence. In conclusion, in normotensive and hypertensive rats, we evidenced the following: 1) full-length CgA directly affects myocardial and coronary function by AkT/nitric oxide synthase/nitric oxide/cGMP/protein kinase G pathway; and 2) the heart generates intracardiac CgA fragments in response to hemodynamic and excitatory challenges. For the first time at the cardiovascular level, our data provide a conceptual link between systemic and intracardiac actions of full-length CgA and its fragments, expanding the knowledge on the sympathochromaffin/CgA axis under normal and physiopathological conditions.

Metabolism ◽  
2001 ◽  
Vol 50 (1) ◽  
pp. 74-78 ◽  
Author(s):  
Dae Ho Lee ◽  
JongUn Lee ◽  
Dae Gill Kang ◽  
Yun Woong Paek ◽  
Dong Jin Chung ◽  
...  

1999 ◽  
Vol 97 (6) ◽  
pp. 697-706 ◽  
Author(s):  
A. BARDEN ◽  
L. J. BEILIN ◽  
K. BOTH ◽  
J. RITCHIE ◽  
P. LEEDMAN ◽  
...  

In order to evaluate whether lipid abnormalities may contribute to endothelial dysfunction in pre-eclampsia, the present study examined the in vitro effects of very-low-density lipoprotein (VLDL), low-density lipoprotein (LDL) and high-density lipoprotein (HDL), isolated from women with pre-eclampsia and matched controls, on the endothelial synthesis of 6-oxo-prostaglandin F1α (6-oxo-PGF1α; a metabolite of prostacyclin) and endothelin 1, and on the expression of nitric oxide synthase 3 (NOS3) mRNA. VLDL, LDL and HDL cholesterol were isolated from 20 pre-eclamptic and 20 age- and gestation-matched normal pregnant women. The lipoproteins (50 μg/ml) and lipoprotein-free control plasma were incubated for 1, 3 and 6 h at 37 °C with a human umbilical endothelial cell line. The synthesis of 6-oxo-PGF1α and endothelin 1, and NOS3 mRNA expression, were measured at each time point. VLDL from pre-eclamptic women stimulated endothelial cell 6-oxo-PGF1α synthesis to a lesser extent than that from normal pregnant women (P< 0.05). LDL from women with pre-eclampsia also stimulated 6-oxo-PGF1α synthesis to a lesser extent than LDL from normal pregnant women, but the effect was less sustained. The effect of HDL from women with pre-eclampsia on 6-oxo-PGF1α synthesis was similar to that of HDL from normal pregnant women. The pre-incubation levels of lipid peroxides in VLDL and LDL were not different between the normal pregnant and pre-eclamptic women, and cannot account for the decrease in 6-oxo-PGF1α synthesis. VLDL, LDL and HDL from women with pre-eclampsia did not affect endothelial cell synthesis of endothelin 1 or expression of NOS3 mRNA differently from lipoproteins from normal pregnant women. This study suggests that VLDL, and to a lesser extent LDL, from women with pre-eclampsia could potentially contribute to the reduced systemic 6-oxo-PGF1α synthesis observed in the pre-eclamptic syndrome.


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